In many instances, it is desirable to secure a nonmetallic fitting to a conduit or hose to secure the hose to another mating fitting. Chemically unreactive nonmetallic fittings are particularly desirable when the hose is to be used in a corrosive environment. Furthermore, nonmetallic hose fittings are cheaper and lighter in weight than conventional metallic hose fittings. In order to produce a fluid tight hose fitting made of a nonmetallic material, it is necessary to provide a fitting which applies constant radial compression about the entire conduit when installed.
The U.S. Pat. No. 4,281,862 to Ridenour discloses another hose fitting assembly. This assembly includes a coupling member for insertion partially within a hose with a plurality of raised ridges thereon to engage the interior of the conduit. A metallic sleeve is disposed about the hose and is disposed over and radially spaced from the portion of the coupling member inserted into the hose. Once the metal sleeve is positioned, a pair of dies engage the sleeve and force the sleeve to engage the conduit to permanently deform the sleeve such that the conduit and sleeve engage the areas between the raised ridges of the inserted portion. The sleeve is, therefore, permanently deformed to prevent removal of the sleeve and the inserted portion from the conduit.
The U.S. Pat. No. 4,519,637 to Folkers issued May 28, 1985 discloses a pipe coupling assembly. This assembly includes a member which is inserted into a conduit and an outer metallic sleeve, which has an axial slit along the entire length of the sleeve, is positioned about the exterior of the conduit. The sleeve has a plurality of teeth on the inner surface thereof for engaging the conduit. An outer collar threadedly engages the inner sleeve and provides an inward force to radially compress the inner sleeve only at the slit; that is, radial compression is not uniform about the entire conduit, and some points about the sleeve are not radially compressed.